In recent years, there has been a known technology by which (i) home electrical appliances installed in a residential building are connected to a network and (ii) a user is notified of the status of one home electrical appliance by use of another home electrical appliance in the vicinity of the user.
For example, Patent Literature 1 discloses a technology in which, in a case where it is determined that a notification of the status of a device should be given to a user, notifying means located in the vicinity of the user is used to notify the user of the status of the device. With the technology, it is possible to efficiently notify the user of statuses of respective devices.